This present embodiments relate to Doppler imaging in ultrasound. Conventional power Doppler mode imaging achieves high sensitivity by using high temporal filtering. As a result, flow dynamics are reduced, resulting in a dull look that may be of less diagnostic value to the user. Also because of spatial filtering, power Doppler may not clearly represent the border between the blood vessel images and the background. As a result, it may be difficult for the viewer to identify small blood vessels accurately.
Directional power or convergent power Doppler incorporates velocity information with the power information using a 2-dimensional color map. The power and velocity information are used as input indices for looking up color values for an image. Although these techniques are able to present flow dynamics, they lack the sensitivity of pure power Doppler. Moreover, it is in general more difficult for a user to decipher multidimensional information from a color map than one-dimensional information such as only velocity or power. In another approach, a derivative of power is used to enhance the imaging. Although this technique has similar sensitivity to traditional power Doppler, the temporal flow dynamics may be missing.